In practice, in a known way with regard to vehicles, a torque generated by a motor is necessarily conducted through a succession of gear trains to driven wheels. If vehicles, such as 4-wheel drive passenger cars or 4-wheel drive trucks are made with a plurality of driven axles, then the torque from the motor must be apportioned in a special gear assembly in the vehicles to the respective drive axles.
For this load apportionment, differential gear trains (hereinafter referred to as “differential(s)”) are installed, whereby a center differential, when seen in the direction of travel, compensates for longitudinal axle spacing (front to back) in apportioning the torque for a plurality of driven vehicle axles. Transverse differentials, i.e., compensating gear trains, are used in regard to the relationship of the direction of travel (curving) of a vehicle to a transverse apportionment of the torque delivered to the driven wheels on a vehicle axle.
Differentials conventionally employed in practice are, among other types, bevel gear differentials, spur gear differentials in planet gear techniques or even worm gear differentials. Especially because of the possibility for non-symmetrical torque distribution, spur gear differentials are mostly installed as central differentials. Bevel gear differentials present, generally, a standard for transverse compensation and worm gear differentials are installed both for length apportionment was well as for transverse load dividing.
The torque produced by the motor is, in the case of a bevel gear differential, introduced into the differential on a worm or hypoid toothed bevel gear, for example, and then transmitted by means of a differential cage onto free pinion gears, which act in the manner of a balance-beam and continually create torque compensation between two output shafts of the bevel gears of the bevel gear differential. In the case of straight line forward travel of a vehicle equipped with the bevel gear differential, then, the differential cage and the pinion, which are bound with rotational capability to the bevel gears, as well as the pinions within a differential cage, all run together as one unit whereby differential bolts and the thereon placed differential pinions contribute or receive no relative motion.
In curve travel operation, a requirement is that a bevel gear shaft, where the bevel gear is on a first output shaft of a differential and which is bound to that axle of a wheel of the vehicle, which is on the outside of the curve, must rotate at a higher speed than that axle shaft, i.e., a second output drive shaft of the differential, which is bound that axle of a wheel on the inner circumference of the curve, whereby the bevel gears and the differential pinions, in a known way and manner, so rotate in relation to one another, that a compensation of the different speeds of rotation is established between the two wheels of a vehicle.
A disadvantage of this arrangement is that the differentials known in conventional practice, which are normally transverse differentials between the motor and wheels, possess such an outer dimensioning that in the relevant installation position, the space available in the presence of a crown gear assembly is not sufficient to also accommodate a conventional differential. In such a case, it becomes necessary to place the differential on that side of the motor which is remote from the crown gear assembly. When this is done, then it becomes necessary that torque from a transmission with an output on the same side of the motor as the crown gear assembly, is conducted by means of an additional torque transfer device to that side of the motor which is remote from the steering gear assembly and to a crown gear of the differential.
Accordingly, the present invention has the purpose of making such a differential available, wherein the introduction of torque into a differential can be conducted on the same side of a motor on which the output of a transmission is located and wherein a crown gear assembly of a differential is also present.